1. Field of the Invention
The present invention relates to an input device for use in a domestic game machine, particularly an input device capable of detecting an acceleration.
2. Description of the Prior Art
Acceleration sensors are usually formed as capacitance type sensors or by using a piezoelectric element and are used in various fields, including such automobile-related components as air bags and suspensions, as well as seismometers and anti-theft devices.
Recently, for enhancing a sense of presence and thereby having experience close to the reality, lifelike input devices have come to be used for business use, including simulation.
However, the acceleration sensor used in the above input devices is very expensive and therefore the use thereof in domestic game machines has so far encountered a problem in point of cost. Besides, in comparison with input devices for business use, those for use in domestic game machines are not required to have a very high accuracy, so there has been a problem in using such an expensive acceleration sensor as referred to above.
The use of the expensive acceleration sensor also involves the problem that the structure of internal circuits becomes complicated.
The present invention has been accomplished for solving the above-mentioned problems and it is an object of the invention to provide an input device of a simple mechanism and capable of being manufactured less expensively.
According to the present invention there is provided an input device wherein an acceleration sensor for detecting an acceleration of a case is disposed within the case, the case being handled by hand, and an output provided from the acceleration sensor is transmitted to a computer or a game machine, characterized in that the acceleration sensor comprises a weight supported by an elastic member and detecting means which causes an electric signal to be varied with a motion of the weight upon an elastic deformation of the elastic member.
This input device can be constructed by combining such simple components as the weight, elastic member, and detecting means, not requiring the use of the expensive acceleration sensor as in the prior art, and can therefore be manufactured less expensively. For this reason, this input device is suitable as an input device not requiring a high accuracy such as an input device in a domestic game machine.
The detecting means used in the present invention may be one which outputs an ON-OFF change-over signal or one which acquires an output varying according to the distance of movement of the weight. In the detecting means which outputs an ON-OFF change-over signal, the result of having detected an acceleration of the case is outputted as a digital value, while in the detecting means which acquires an output varying according to the distance of movement of the weight, the result of having detected an acceleration of the case is outputted as an analog value.
The former detecting means may be a switch adapted to operate and self-reset upon arrival at a predetermined position; for example, it may be such a conventional switch as a mere contact change-over switch or a proximity switch. Also as to the latter detecting means, it is may be a conventional one such as a volume control type which detects a change in resistance.
In the present invention, the weight may be supported by the elastic member so as to be movable in both a first direction and a second direction opposite to the first direction, and there may be used a first detecting means which is operated by movement of the weight in the first direction and a second detecting means which is operated by movement of the weight in the second direction.
With these detecting means, it is possible to make detection in two directions.
The input device according to the present invention may be provided with first and second weights of different masses, a first elastic member which supports the first weight, a second elastic member which supports the second weight, and detecting means which are operated by the first and second weights, respectively, when both weights move in the same direction.
For example, in the case where the mass of the first weight is heavier than that of the second weight and where the same acceleration is applied to both weights, the first detecting means can detect a change in an electric signal earlier than the second detecting means, and by detecting a time difference between such changes it is made possible to detect the acceleration.
Preferably, the first and second elastic members are the same in elastic modulus. By so doing, the acceleration to be outputted can be adjusted by changing only the weight mass.
Alternatively, the mass of the first weight and that of the second weight may be made equal to each other and there may be used elastic members different in elastic modulus.
Preferably, there is used a rotatable input member and the weight is movable in a direction in which a centrifugal force is exerted by the rotating motion of the input member.
For example, in case of an input device whose shape is similar to a bat in baseball, a golf club, or a fishing rod, it is mounted on a tip end of its case, whereby the speed and the instant of impact are detected upon a swing motion of the input device.
The elastic member may be a coiled spring or a member capable of undergoing deflection.
For example, in case of a coiled spring, the coiled spring can be disposed between the weight and the detecting means, whereby the coiled spring is deformed when a force having an acceleration toward the detecting means is applied to the weight, and the detecting means is operated by the weight. In case of a member capable of undergoing deflection, the detecting means is disposed in a deflecting direction with respect to the weight.